chore(travis): check for travis secure envs (#1022)
chore(travis): check for travis secure envs (#1022)

Travis only expands secure envs for commits directly from cerebral/cerebral. Check if they exist
before using them so that PRs from forks can be tested.
fopsdev/cerebral,fopsdev/cerebral,christianalfoni/cerebral,garth/cerebral,cerebral/cerebral,garth/cerebral,cerebral/cerebral,christianalfoni/cerebral